kernel: Enable PPP_FILTER by default.

pppd will try to use it to improve efficiency and complain if it's not available
(but is is not mandatory).
docker: propagate nix.proxy into daemon environment
new package: ccnx
cabal: add "-hidir $TMPDIR" parameter to ghc call that compiles Setup.hs

Packages that don't have a Setup.hs file get to use a default version that
lives in the Nix store. By default ghc tries to put the Setup.o and Setup.hi
files in the same directory as the source file, which isn't writable. This
leads to build errors [1]. Thus, we re-direct those paths to a build-local
writable location: $TMPDIR.

Arguably, we could also use "." or copy the /nix/store/deadbeef-Setup.hs file
into the local source directory before compiling, which would work fine, too.

[1] https://github.com/NixOS/nixpkgs/issues/4851
haskell-Extra: update to version 1.46.3
haskell-HaTeX: update to version 3.15.0.0
haskell-extra: update to version 0.7
haskell-generic-aeson: update to version 0.2.0.2
haskell-generic-deriving: update to version 1.7.0
haskell-hindent: update to version 3.9.1
haskell-hspec-meta: update to version 1.12.3
haskell-hspec: update to version 1.12.3
haskell-json-schema: update to version 0.7.1.1
haskell-tagged: update to version 0.7.3
haskell-atomic-primops: update to version 0.6.1
haskell-bifunctors: update to version 4.2
haskell-classy-prelude-conduit: update to version 0.10.2
haskell-classy-prelude: update to version 0.10.2
haskell-conduit-combinators: update to version 0.3.0
haskell-conduit: update to version 1.2.2